2 Zeners versus 1 zener- inconsistent with actual theory?

  • Thread starter wushumaster
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In summary, when two zeners are connected in series, the voltage drop should be less than when only one is used. However, when using two equal-value zener diodes in parallel, the voltage drop may be slightly less due to the splitting of current between the two diodes. This behavior is explained by the characteristics of zener diodes and their use in regulating voltage in electronic circuits.
  • #1
wushumaster
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So when I have two zeners connected, I should get less voltage than if I had one, but this is NOT the case! Why?
I don't understand- two zeners of say 1000 V each- say we have a power source than provides 2500 volts- then we should get only 500 V. With one of these zeners, we should get 1500 V. But it's almost reversed, and I don't get why..
Thanks!
 
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  • #2
wushumaster,

You should probably include some details like how the zeners are connected. Next you should explain why on Earth you are attempting to use zeners with a 2500V supply. You should probably include some details about your supply voltage, at the very least confirm that it is a DC supply.

Fish
 
  • #3
wushumaster said:
So when I have two zeners connected, I should get less voltage than if I had one, but this is NOT the case! Why?
I don't understand- two zeners of say 1000 V each- say we have a power source than provides 2500 volts- then we should get only 500 V. With one of these zeners, we should get 1500 V. But it's almost reversed, and I don't get why..
Thanks!

When you connect two zeners in series, the overall voltage drop is the sum of the two zener voltages.

When you connect two equal-value zener diodes in parallel and drive them with a current source, the voltage drop is slightly less than when you have just the one zener diode. That is because the two parallel zener diodes are splitting the available current, so each diode voltage is a little less since it's running at a lower current.

http://en.wikipedia.org/wiki/Zener_diode

.
 
Last edited:

1. What is the difference between using 2 Zeners and 1 Zener in a circuit?

Using 2 Zeners in a circuit allows for a larger voltage range to be regulated compared to using only 1 Zener. This is because the breakdown voltage of 2 Zeners can be added together, whereas with 1 Zener, the breakdown voltage is limited to the single Zener's value.

2. Why does using 2 Zeners sometimes provide inconsistent results with the expected theory?

The theory behind using 2 Zeners is based on the assumption that both Zeners have the same breakdown voltage and characteristics. However, in reality, this may not always be the case and can lead to inconsistent results. Other factors such as temperature and manufacturing variations can also affect the performance of the Zeners.

3. Can using 2 Zeners instead of 1 increase the accuracy of voltage regulation?

Using 2 Zeners does not necessarily increase the accuracy of voltage regulation. While it does allow for a wider voltage range, the accuracy still depends on the Zener's breakdown voltage and characteristics. Other components in the circuit, such as resistors, also play a role in regulating the voltage.

4. Are there any advantages to using 1 Zener over 2 Zeners in a circuit?

Using 1 Zener can be advantageous in certain cases where a specific voltage range needs to be regulated. In this scenario, using 1 Zener with the desired breakdown voltage can provide more precise regulation compared to using 2 Zeners with their combined breakdown voltage.

5. Are there any potential risks or drawbacks to using 2 Zeners instead of 1?

The main drawback of using 2 Zeners is the potential for inconsistent results due to variations in the Zener's characteristics. This can lead to inaccurate voltage regulation and potential damage to other components in the circuit. It is important to carefully select and test the Zeners before using 2 in a circuit.

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